Dynamic competition between Cooper pair and spin density wave condensation

Quantum matter phases may coexist microscopically even when they display competing tendencies. A fundamental question is whether such a competition can be avoided through the elimination of one phase while the other one condenses into the ground state. Here, we present a high-resolution neutron spec...

Full description

Saved in:
Bibliographic Details
Main Authors: B. Decrausaz, M. Pikulski, O. Ivashko, N. B. Christensen, J. Choi, L. Udby, Ch. Niedermayer, K. Lefmann, H. M. Rønnow, J. Mesot, J. Ollivier, T. Kurosawa, N. Momono, M. Oda, J. Chang, D. G. Mazzone
Format: Article
Language:English
Published: American Physical Society 2025-05-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.7.023131
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Quantum matter phases may coexist microscopically even when they display competing tendencies. A fundamental question is whether such a competition can be avoided through the elimination of one phase while the other one condenses into the ground state. Here, we present a high-resolution neutron spectroscopy study of the low-energy spin excitations in the high-temperature superconductor La_{1.855}Sr_{0.145}CuO_{4}. In the normal state, we find low-energy magnetic fluctuations at incommensurate reciprocal lattice positions where spin-density-wave order emerges at lower Sr concentration or at high magnetic fields. While these spin excitations are largely suppressed by the emergence of the superconducting spin gap, some low-energy magnetic fluctuations persist deep inside the superconducting state. We interpret this result in terms of a dynamic competition between superconductivity and magnetism, where superconductivity impedes the condensation of low-energy magnetic fluctuations through the formation of magnetically mediated Cooper pairs.
ISSN:2643-1564